Simultaneously enhanced thermal conductivity and mechanical performance of carbon nanotube reinforced ZK61 matrix composite

Alloying seriously deteriorates the thermal conductivity of magnesium (Mg) alloys, thus, restricts their applications in the fields of computer, communication, and consumer products. In order to improve the thermal conductivity of Mg alloys, adding carbon nanotube (CNT) combined with aging treatment is proposed in this work, i.e. fabricating the D-CNT (a kind of dispersed CNT) reinforced ZK61 matrix composite via powder metallurgy, and conducting aging treatment to the composite. Results indicate the as-aged ZK61/0.6 wt.% D-CNT composite achieved an excellent thermal conductivity of 166 W/(mK), exhibiting 52.3% enhancement in comparison with matrix, as well as tensile yield strength of 321 MPa, ultimate tensile strength of 354 of MPa, and elongation of 14%. The simultaneously enhanced thermal conductivity and mechanical performance are mainly attributed to: (1) the embedded interface of the D-CNT with matrix and (2) the coherent interface of precipitates with matrix. It is expected the current work can provide a clue for devising Mg matrix composites with integrated structural and functional performances, and enlarge the current restricted applications of Mg alloys.